One of the devices I have with the appropriate 5V buffer battery for more than two years in constant operation, works in all seasons and in all weathers. Until now had never problems.
The cables and terminals are top and make no trouble, no rust or the like.
The mounting by rubber ring has logically after two years no longer held so well (sun, salt water in winter, frost). Thanks to the recesses in the mounting bracket but wars extremely easy, the rubber rings by high-tech (= cable ties) to replace.
All in all, highly recommended if you want to run additional electrical equipment on the bicycle / needs.